In an aircraft, various movable elements such as control surfaces or indeed the cowl of a thrust reverser are associated with actuator members in order to be moved between a neutral position and an active position. For this purpose, the actuator members are driven by a motor to move in translation between two abutments. By way of example, for a flap, a first abutment is associated with the neutral position of the movable element, and a second abutment is associated with the active position of the movable element. Under such circumstances, when the motor is powered, it drives the actuator members that in turn move the associated movable members.
Nevertheless, the rotor of the motor might be subjected to mechanical blocking. In spite of the blocking, the electrical power that is delivered to the motor remains identical, thereby leading to overheating of the motor, and in particular of its power electronics. This can lead to degradation of the motor.
One solution would be to design the power electronics of the motor in such a manner as to enable it to withstand overheating as a result of the rotor being blocked. However, that would lead to an increase in the weight and in the size of the power electronics, which is not desirable in the field of aviation.
Another solution would be to detect overheating by means of a thermal relay. Nevertheless, such a relay presents a response time that is relatively long and therefore does not enable overheating to be detected quickly. The power electronics could thus still be damaged in spite of the presence of the relay. Furthermore, the relay does not make it possible to distinguish between a problem of overheating due to a genuine blockage of the rotor, and a problem of overheating due to some other reason. Any action taken after the relay has detected overheating might therefore not be appropriate.